Help - not sure what to do

I had a doe kindle yesterday. Kits are all fine and doe seemed fine. This morning I took her out of her cage and when I turned her over I noticed that her vulva was very swolen. It is very pale and even looks like a large blister. When push back it opens and look completely normal. I am afraid she go frost bitten. It was -5 when she kindled and the temp has not gotten over 8 since. Any ideas what this may be and how to treat it? I filled her cage with straw so she would not be sitting on the freezing wire but am at a loss for what else to do.
Any advise would be appriciated. Thanks.

I agree ,, I would 'think' its just from her giving birth ,, if you have her cage filled with straw for her to snuggle down in and are keeping her food and plenty of water ,,

at 8 degrees I know thats hard to do ,,,, when we have freezing temperatures that go below freezing and 'stay' below during the day ,, I will take the plastic freezer containers (or old butter tubs) ,, fill with water and freeze ,, and I will put a block of ice in each rabbits cage ,, so when their water bottle freezes they will have the ice to lick on ,,, seems to help

She should be fine ,, are you leaving the nestbox out in her cage with her or are you bringing it inside and just taking out early am and last thing pm ??